Adhesive applicator



Oct. 27, 1970 e. A. EISERT 3,536,411

' ADHESIVE APPLIGATOR Filed April 7, 1969 l N VEN TOR.

GER-ALD'A. EISERT BY AT TORNEYIS United States Patent 3,536,411 ADHESIVE APPLICATOR Gerald A. Eisert, Hastings, Minn., assignor to Central Research Laboratories, Inc., Red Wing, Minn., a corporation of Minnesota Filed Apr. 7, 1969, Ser. No. 813,876 Int. Cl. 343k 5/06 U.S. Cl. 401176 8 Claims ABSTRACT OF THE DISCLOSURE This invention relates to a device for manually applying a viscous liquid, such as an adhesive, in a thin uniform stripe layer, particularly between overlapped surfaces. In many plastic fabricating operations it is necessary to adhesively secure together overlapped surfaces in a tight adhesive seal forming a seam which is as smooth and uniform as possible. Where this is done manually it is difiicult to apply a relatively thick viscous liquid adhesive in a thin uniform stripe. Particular difficulties are encountered where the overlapped surfaces are closely fitted, as is true in securing two cylindrical plastic sleeves together. The applicator of the present invention facilitates such sealing operations.

The applicator according to the present invention is illustrated in the accompanying drawings in which corresponding parts are identified by the same numerals and in which:

FIG. 1 is a side elevation of the applicator;

FIG. 2 is a longitudinal section on the line 2-2 of FIG. 1 and in the direction of the arrows; and

FIG. 3 is a transverse section on the line 3-3 of FIG. 1 and in the direction of the arrows.

Referring now to the drawings, the applicator comprises a cylindrical body 10 which is open at one end and closed at the other by means of end wall 11 to enclose a cuplike reservoir 12. A central stem extends outwardly from the body end wall 11. Stem 13 is elongated, having a length several times the depth of the body 10. Stem 13 is generally cylindrical at its base adjacent the body end wall and then tapers inwardly toward its longitudinal axis as it extends outwardly from the body to define a relatively fiat side-discharge dispensing nozzle portion 14.

As best seen in FIG. 3, While the nozzle portion of the applicator is generally fiat, it desirably has an air foil configuration in cross section with a blunt flat tapered knife edge leading edge 15 and a slightly thicker trailing edge 16 having an elongated dispensing slot 17 therein. Stern 13 terminates in an arcuate tapered tip 18 having a blunt pointed closed end. Dispensing slot 17 is fiat and narrow in cross section. It extends from adjacent the longitudinal center line of the stem flaring outwardly to the trailing edge 16 of the generally fiat end portion of the stern. A channel 19 extends along the longitudinal axis of the stem from reservoir 12 in the body to the slot 17. Channel 19 is of generally circular cross section and of relatively small diameter. Desirably the portion of channel immediately adjacent to reservoir 12 is of slightly larger diameter as shown.

A cylindrical plunger 20 fits with a close slide fit in the body in reservoir 12. The plunger 20 is of a length just slightly greater than the depth of reservoir 12 and its inside end conforms to the configuration of the inside of 3,536,411 Patented Oct. 27, 1970 ice end wall 11 so as to permit substantially complete expulsion of all material in the reservoir. Plunger 20 is provided with a flat knob 21 to permit retraction of the plunger and having a low profile convex surface adapted to fit comfortably against the palm of the operator using the applicator.

Preparatory to use of the applicator the plunger 20 is removed from the reservoir 12 and the reservoir is partially filled with the viscous liquid to be applied, such as a viscous adhesive. The end of the plunger is inserted into the open end of the body and pushed in so as to press against the material contained in the reservoir. Air is bled from the reservoir by holding the unit with dispensing nozzle 14 uppermost and depressing the plunger until liquid appears at the nozzle. The applicator is placed with the flat surface of the dispensing nozzle 14 against the surface onto which the liquid material is to be applied. Where that surface lies between overlapped sheets or sleeves or the like, the bluntly pointed tip 18 and tapered leading edge 15 facilitate insertion of the nozzle.

The body is grasped with fingers against the outside of end wall 11 on opposite sides of stem 13 and with the knob 21 of the plunger 20 resting against the palm of the same hand. As the applicator is moved along the surface to which the viscous liquid is to be applied, pressure is gently exerted by the palm against the plunger to push out through the slot 17 the required amount of material.

Where the edges of the material being sealed are overlapped the air foil shape of the dispensing nozzle facilities movement of the applicator in the direction of the leading edge 15. The thickened intermediate portion of the generally flat dispensing nozzle slightly separates the overlapped layers to leave a small space into which the adhesive is extruded from the slot 17 in the trailing edge 16 of the nozzle.

The adhesive may be applied rapidly in a uniform strip, even between closely fitting overlapped edges. The design of the applicator permits substantially complete expulsion of the material from the reservoir. The plunger may then be withdrawn and the reservoir refilled for further use.

The applicator may be formed from metal, such as steel, aluminum, brass, or the like, in which case it is cleaned of residual adhesive after each use. Alternatively, the applicator may be disposable, molded from synthetic resinous plastic material not incompatible with the liquid to be applied, in which case the applicator may be discarded after use. A close fitting cap may be provided to slip over the dispensing nozzle of the applicator to prevent premature hardening or setting up of the adhesive when the applicator is not being used. While the reservoir and plunger are shown as being circular in cross section, they may obviously be of other geometrical shapes, square, hexagonal, or the like, so long as they mate in a close slide fit.

The body and plunger when assembled should be of a size to fit comfortably in the hand of the operator. For example, the body 10 is about 1% inches in diameter and about 1% inches deep; the plunger 20 is about 1 /2 inches in diameter and about 2 inches deep. The stem 13 at its base is about /2 inch in diameter and the dispensing nozzle 14 is about inch thick. The stem should, of course, be of a length as required by the particular fabricating job. While the stem is ordinarily rigid, it may be flexible where required for access to the surfaces to which adhesive is to be applied. While the stem is shown as coaxial with the body it may be off-center or may project obliquely or transversely of the body to meet particular fabricating needs.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A hand held and manually operable applicator for spreading viscous liquids in confined spaces which comprises:

(A) a hollow body open at one end and closed at the other and enclosing a reservoir for said liquid,

(B) an elongated stem extending outwardly from the closed end of said body,

(C) the outermost end of said stem being generally flattened,

(D) at least one restricted lateral discharge aperture in one only of the narrow side edges of said outermost flattened end of the stem adjacent the tip thereof, the opposite side edge of said tip being closed to the passage of liquid,

(E) a longitudinal channel through said stern connecting said reservoir and said discharge aperture, and

(F) a closely fitting plunger in the open end of said body.

2. An applicator according to claim 1 further characterized in that said discharge aperture is a narrow elonggated slot.

3. An applicator according to claim 1 further characterized in that said body and stem are in axial alignment.

4. An applicator according to claim further characterized in that the outermost generally flattened end of said stem is thicker along the trailing edge having said discharge aperture therein and having a fiat tapered leading edge generally parallel thereto.

5. An applicator according to claim 1 further characterized in that the outer end of said plunger is provided with a low profile convex palm engaging surface and with means for retracting said plunger from the reservoir.

6. An applicator according to claim 1 further characterized in that said body is of a size to permit grasping of the closed end of the body with two fingers and engagement of the outer end of said plunger by the palm of the same hand.

7. An applicator according to claim 1 further characterized in that said reservoir and said plunger are cylindrical.

8. An applicator for spreading viscous liquids which comprises:

(A) a hollow cylindrical body open at one end and closed at the other and enclosing a reservoir for said liquid,

(B) an elongated stern extending outwardly from the closed end of the body in axial alignment with the body,

(C) the outermost end of said stem being generally flattened with a fiat tapered leading edge and a thicker trailing edge generally parallel thereto,

(D) a narrow elongated slot discharge aperture in the trailing edge of the outermost end of the stem adjacent the tip thereof,

(E) a longitudinal channel through the stern connecting said reservoir and said slot,

(F) a closely fitting cylindrical plunger in the open end of said reservoir, said plunger being provided with a low profile convex palm engaging end surface and with means for retracting the plunger from the reservoir, and

(G) said body being of a size to permit grasping of the closed end of the body with two fingers and engagement of the outer end of the plunger by the palm of the same hand.

References Cited UNITED STATES PATENTS 10,480 2/1902 Norway.

LAWRENCE CHARLES, Primary Examiner US. Cl. X.R. 401-266 10/1932 Lowder 40l266' P0405) UNITED STATES PATENT OFFICE (56g CERTIFICATE OF CORRECTION Patent No. 3,536,411 Dated October 27, 1970 Inventor(s) Gerald A. eIt

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 29, "facilities" should be --facilitates.

Column 3, line 24, after "claim" l is omitted.

\"s I "LU SERLED JAN 5 1971 SEAL) 1mm: m

mm E.

Edward 32225 Gomissionar of Faun Auesling 

